Fix issue with unhandled error on Stat

If stat returns an error other than the directory not existing
it was unhandled. When IsDir is called in one of these situations
it causes a panic.

Closes #8181

Signed-off-by: Matt Farina <matt@mattfarina.com>
(cherry picked from commit f182ebc11c)

pkg/chartutil/save.go

@@ -103,12 +103,17 @@ func Save(c *chart.Chart, outDir string) (string, error) {
 
 	filename := fmt.Sprintf("%s-%s.tgz", c.Name(), c.Metadata.Version)
 	filename = filepath.Join(outDir, filename)
-	if stat, err := os.Stat(filepath.Dir(filename)); os.IsNotExist(err) {
-		if err := os.MkdirAll(filepath.Dir(filename), 0755); err != nil {
-			return "", err
+	dir := filepath.Dir(filename)
+	if stat, err := os.Stat(dir); err != nil {
+		if os.IsNotExist(err) {
+			if err2 := os.MkdirAll(dir, 0755); err2 != nil {
+				return "", err2
+			}
+		} else {
+			return "", errors.Wrapf(err, "stat %s", dir)
 		}
 	} else if !stat.IsDir() {
-		return "", errors.Errorf("is not a directory: %s", filepath.Dir(filename))
+		return "", errors.Errorf("is not a directory: %s", dir)
 	}
 
 	f, err := os.Create(filename)